1. Field of the Invention
The present invention relates to subsea pipe connection assemblies. More particularly, the present invention the relates to apparatus and methods for connecting a first flange to a second flange in a subsea location. More particularly, the present invention the relates to remotely-operated vehicle ROV-delivered tools for effectively connecting the flanges together.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
There are various recognized methods of diverless connection of underwater flow lines and pipelines to underwater structures. The methods used for such connections characterized mainly by two principle factors. These factors include the use of permanently installed underwater hardware known as tie-in porches or reaction structures in the strict dependency upon the related connection system (connector). Both the permanently installed underwater hardware and connection systems have critical parameters. The items of hardware required to support the connection operations are usually installed during flowline or pipeline structure installation. Any deviation from the standard procedures required by the installers can result in a very high cost impact. This can make the system less competitive than other alternative options.
In particular, under certain circumstances, it may be desirable to connect a gas flow pipeline installed in one location to a gas flow pipeline installed at another location. In normal circumstances, in order to allow the ability to tap into another subsea well, various valves are operated and operations are needed so as to change the gas flow lines. Typically, it is necessary to connect the pipeline to a manifold and then to a ship. As such, it would be normal to cut the pipeline, bring the pipeline to the surface and then connect the pipeline to another pipeline. The pipeline is cut off generally adjacent to the valves. This is very complicated, time-consuming and expensive operation. This is especially the case when the flange connections between the pipelines are located at very deep subsea location.
In the past, various patents have issued relating to the ability to connect pipelines in subsea locations. For example, U.S. Pat. No. 6,767,165, issued on Jul. 27, 2004 to G. Corbetta, describes a method and apparatus for connecting underwater conduits. This method includes the steps for launching a remotely-operated vehicle from a support vessel, launching connection operations from the support vessel, manipulating the remotely operated vehicle to dock with the connecting apparatus, installing of the connection apparatus to one of the conduits, activating a docking clamp using the remotely operated vehicle to capture the end of the first conduit, activating the connection apparatus to draw the second conduit to the first, connecting the two conduits together to form a continuous flowline, providing a sealed connection and then recovering the remotely-operated vehicle and connection apparatus to the support vessel.
U.S. Pat. No. 5,273,376, issued on Dec. 28, 1993 to P. B. Ritter, Jr., describes back-up connector release tool. This is an emergency release tool for operation by a remotely-operated vehicle (ROV) for forcefully releasing a riser from a subsea well assembly. The tool includes hydraulic cylinders mounted on a frame that can be positioned by the remotely-operated vehicle to surround the risers. The cylinders are pressurized to forcefully remove the riser from the wellhead assembly.
U.S. Pat. No. 4,548,273, issued on Oct. 22, 1985 to Leicht et al., teaches a torque multiplier subsea tool for setting a seal between a casing hanger and a subsea wellhead. This tool includes a mandrel having a sun gear with axial elongate teeth. An outer barrel is disposed around the mandrel forming an annulus therebetween. A planetary gear assembly is disposed in the annulus between the barrel and the sun gear to transmit to the barrel a torque which is higher in magnitude than that applied to the mandrel. A connector body is disposed around the mandrel, below the planetary gear assembly, and includes radially movable dogs for engaging the casing hanger. The barrel engages the sealing assembly and transmits the increased torque thereto to advance the sealing assembly downwards and to set the seal.
In those circumstances where a pipe flange must be connected to another pipe flange, it has been difficult to effectively install studs and tighten nuts associated with the studs so as to effectively engage one pipe flange with the other pipe flange. Although torquing tools are known for the tightening of nuts associated with studs of flanges, it is very difficult to effectively manipulate an ROV so as to place the torquing tool into a desired location with respect to the nut of the stud.
Additionally, it is often difficult to position the nut in proximity to the desired holes of the pipe flange connection. As such, there is a need to have mechanisms and methods whereby a new pipe connection can be made to an existing pipe connection in a subsea location. In addition, there is a need to provide a tool whereby the nuts on the studs associated with such pipe flange connections can be effectively installed in an effective manner.
It is an object of the present invention to provide an apparatus for connecting pipe flanges which can be effectively utilized in a subsea location.
It is another object of the present invention to provide an apparatus and method for connecting pipe flanges whereby the components of the pipe flange connection can be delivered by an ROV.
It is a further object of the present invention to provide a pipe flange connection assembly whereby the studs associated with the flanges are assuredly properly aligned with associated nuts.
It is still a further object of the present invention to provide an apparatus and method for connecting pipe flanges in a subsea location which allows an ROV to properly align a torquing tool with each of the nuts associated with the studs of the pipe flange connection.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.